Getting OUT of the US isn't the problem. I've found that getting back IN is. If I were you, I would keep your itinerary as is, and take the Cascades to get back into the country from Vancouver, BC. It's a sealed train, and there is no delay at the border like there is at Rouse's Point and Niagara Falls.

While the train does run sealed through Canada, the southbound Cascades DOES stop at the border to do Customs inspection (US Immigration is done in the Vancouver station). However, having ridden the Cascades (a lot), as well as the Maple Leaf and the Adirondack, the Customs only inspection at Blaine is briefer and much easier than either the Maple Leaf or the Adirondack.

One exception about smooth transit through the Blaine Customs inspection on the US bound Cascade is if they happen to have some tipoff on illicit materials on the train. At that point all bets are off. Has happened to me once.

I do not think Prestige class is worth it UNLESS you are loaded with disposable funds. Some elderly (and disabled) friends from Orlando did Prestige class last year. The wife, who is disabled, loved it. The husband, who is able-bodied, and paid the bill, did not think it was worth it (other than making his wife happy).

When I took the Canadian in Dec 2010, I got an express deal and paid next to nothing for a room for 2. Things are different now.

Winnipeg holds a special place for me. Going outside in Winnipeg was the only time in my life that I experienced below zero F temperature. It was 15 below and I did not stay outside long.